[mschuster91]

It is possible for them to extract the MRZ data of the passport (the Machine Readable Zone), it contains the passport ID, issuer state, DOB and DOE.

I don't know if the regulatory requirements state that you must keep a photocopy, but in case you do not it would be foolish to store more data than you need.

[alcari]

That may be possible, but they also accepted non-passport images, which don't necessarily have such information.